The combination of the discovery, development, and exploitation of antibiotics was one of the most significant advances in medicine in the 20th century. Virtually all current antibiotics with clinical utility were identified during the so-called 'golden' period of discovery between the 1940's and 1960's and their implementation produced impressive reductions in the burden of disease caused by bacterial infections. Unfortunately, the widespread emergence of acquired resistance to antibiotics in bacteria over the last three decades now constitutes a serious threat to global public health. Thus, there is an important demand for the discovery and development of new classes of antibiotics to add our current arsenal and an urgent need for new drug discovery strategies. Natural products have historically been the single most productive source of drug leads, including antibiotics, yet screening of these secondary metabolites has recently fallen out of favor. For microbial-produced natural products, this is largely the result of the extremely high (99%) rediscovery rate, which occurs as a result of isolation, and testing of the same organisms again and again. This high rediscovery rate supports recent work suggesting that less than 1% of microbial diversity has been cultured and studied experimentally, and that the remaining 99% is not readily amenable to laboratory cultivation. Using this generally accepted theme as a starting point, novel media, media supplements, and cultivation conditions will be utilized to isolate microorganisms from a variety of natural, under-explored environments in Alabama. Microbial cultivations will be combined with fermentation and genetic screening to identify organisms that are capable of producing secondary metabolites. These studies are aimed at increasing our understanding of the problems associated with the isolation of microorganisms from natural environments and of the conditions required to increase production of secondary metabolites. The specific aims of the proposed project include: 1) to determine what approaches are necessary to increase the percentage of microorganisms isolated from natural environments; 2) to determine what growth factors/additions/manipulations will initiate production of secondary metabolites in fermentation broths; and 3) to determine which organisms possess biosynthetic pathways for the production of potentially useful secondary metabolites. [unreadable] [unreadable]